The secret key is KY3OUPMUYWCKS53F for the above URL. It is base32 encoded by default. You will be able to get the URL by using a QR code scanner during 2-step verification setup.

Once you have the secret key, use oathtool using the following command syntax.

# oathtool --totp -b -d 6 KY3OUPMUYWCKS53F

The above command will switch oathtool to TOTP mode, use base32 encoding for the key and display 6 digits for the OTP password.

Since TOTP codes are generated based on current timestamp, the system time must be accurate in order for oathtool to generate valid verification codes. If oathtool is generating invalid codes, check your system time.